Réaction #887

Équation de réaction

1,2-dibromo-1,2-di(4-bromobenzoyl) ethane

sodium 4-methyl phenoxide

4-methylphenol

→

1-(4-tolyloxyl)-1,2-bis(4-bromobenzoyl)ethylene

Solvants

THF

THF

Conditions de réaction

Traitement

1. 1
   Autrewas removed under reduced pressure
2. 2
   workup.ADDITIONThe residue was treated with water
3. 3
   Filtrationthe solid was filtered
4. 4
   Lavagewashed with water
5. 5
   Séchagedried (Na2SO4)
6. 6
   workup.DISSOLUTIONdissolved in chloroform
7. 7
   LavageThe chloroform solution was passed through a silica column (elution with 2-5% ether in hexane)

Mode opératoire

To a solution of 1,2-dibromo-1,2-di(4-bromobenzoyl) ethane (11.1 g, 0.02 mole) in 35 ml of THF was added a suspension of sodium 4-methyl phenoxide [prepared from 0.92 g (0.04 mole) Na and 4.32 g (0.04 mole) 4-methylphenol in 30 ml THF by refluxing for 4-5 hr]. The yellow mixture was refluxed for 2-3 hr (TLC followed) after which the THF was removed under reduced pressure. The residue was treated with water, and the solid was filtered, washed with water, dried (Na2SO4), and dissolved in chloroform. The chloroform solution was passed through a silica column (elution with 2-5% ether in hexane). The result was an off white crystalline solid, 4.95 g (50%), mp 137°-8° C. IR (KBr) 3087, 3035, 2868, 1687, 1646, 1587, 1572, 1557, 1502, 1399, 1364, 1194, 1068, 1009, 971, 876, 815, 772, 526. 1H NMR (CDCl3 /35° C.) 7.92 (d, 2H, J=8.8), 7.65 (d, 2H, J=8.8), 7.55 (d, 2H, J=8.8), 7.48 (d, 2H, J=8.8), 7.27 (d, 2H, J=8.3), 7.11 (d, 2H, J=8.3), 6.32 (s, 1H), 2.4 (s, 3H). 13C NMR (CDCl3 /35° C.) 189.4, 187.6, 168.4, 150.9, 136.6, 136.0, 133.4, 132.3, 131.8, 130.9, 130.3, 129.6, 129.2, 128.2, 120.6, 101.8, 20.95. MS m/e 500 (M+).

Source